Fix `CoreImage` import; remove "AccessLevelOnImport"

FirebaseVertexAI/Sources/PartsRepresentable+Image.swift

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 import CoreGraphics
-import CoreImage
 import UniformTypeIdentifiers
 
 #if canImport(UIKit)
@@ -22,6 +21,10 @@ import UniformTypeIdentifiers
   public import AppKit // For NSImage extensions.
 #endif
 
+#if canImport(CoreImage)
+  import CoreImage
+#endif
+
 private let imageCompressionQuality: CGFloat = 0.8
 
 /// An enum describing failures that can occur when converting image types to model content data.

Package.swift

@@ -1310,9 +1310,6 @@ let package = Package(
       ],
       path: "FirebaseVertexAI/Sources",
       swiftSettings: [
-        // TODO(#14638): Remove "AccessLevelOnImport" experimental feature declaration after
-        // upgrading to `swift-tools-version:6.0`, where it is on by default.
-        .enableExperimentalFeature("AccessLevelOnImport"),
         .enableUpcomingFeature("InternalImportsByDefault"),
       ]
     ),
@@ -1331,9 +1328,6 @@ let package = Package(
         .headerSearchPath("../../../"),
       ],
       swiftSettings: [
-        // TODO(#14638): Remove "AccessLevelOnImport" experimental feature declaration after
-        // upgrading to `swift-tools-version:6.0`, where it is on by default.
-        .enableExperimentalFeature("AccessLevelOnImport"),
         .enableUpcomingFeature("InternalImportsByDefault"),
       ]
     ),